Fifty-nine percent of Democrats surveyed said they would back Granholm in a primary, while 13 percent backed Rep. Gary Peters, D-Mich., 6 percent supported Rep. Dan Kildee, and 23 percent of respondents said they were undecided.

Meanwhile, Romney — the brother of the GOP’s 2012 presidential nominee — leads the potential Republican field with 26 percent of those surveyed. Rep. Mike Rogers came in second with 17 percent support, followed by Rep. Justin Amash with 11 percent. Thirty-seven percent said they were unsure of whom they supported.

The new numbers come just a couple days after Sen. Carl Levin, D-Mich., announced his retirement, opening the floodgates of potential candidates interested in his seat.

Here’s a look at the current field of possible contenders:

Democrats:

Debbie Dingell, the politically active wife of longtime Rep. John Dingell, is considering a run, CNN reported on Monday. Dingell did not immediately respond to an email seeking comment on Tuesday.

Granholm had no comment on the Senate race, according to her spokeswoman. About a month ago, Granholm left her Current TV program. She ended her gubernatorial tenure with low approval ratings but more recently had delivered one of the most rousing speeches at the 2012 Democratic National Convention.

A handful of news reports also mentioned Kildee, a freshman, as potential candidate.

Former Rep. Mark Schauer has not issued a public statement on the race, but sources continue to suggest the former one-term congressman as a potential candidate. Schauer did not return a request for comment.

Republicans:

Rogers, chairman of the House Intelligence Committee, told the Detroit Free Press on Saturday that he is giving the race “serious consideration.”

Amash told the Detroit News on Monday that he is “certainly open” to running in 2014.

Former state GOP Chairman Saul Anuzis told CQ Roll Call on Friday that a run was on the table but not a certainty.

Former Michigan Secretary of State Terri Lynn Land continued to express her interest in the seat on Tuesday, saying she is “very interested” in the race and considers it “a great opportunity” in a brief phone interview.

The conservative website Conservative Intelligence Briefing commissioned the survey of 1744 likely 2014 voters. The margin of error was 2.35 percent. On the GOP side, 615 Republicans were surveyed with a 3.95 percent margin of error. The Democratic sample size was 687 with a 3.74 percent margin of error.

The poll was conducted March 9-10.

Updated 7:06 p.m.

Harper Polling originally referred to “Scott Peters” instead of “Gary Peters” in its polling memo about this race. When questioned by CQ Roll Call, the GOP firm’s founder, Brock McCleary, said the discrepancy was a typo. He also produced polling scripts and other supporting documentation, such as survey cross tabs, that referred to the candidate as “Gary Peters.”